If i was you then i would give 1/3 strenth nutes as it does look as though its wanting food as the little water leafs at the bottom of your plant are starting to die , Thats a sign to start giving nutes but as your plants are REALLY SMALL for that age i would start off REALLY light on the nutes as nubies tent to over feed . I think you will be ok , Heres a couple of pics of my plants that are just over 2 weeks old . Not going to start giving nutes until another 3 - 4 weeks .
The pic of the plant by itself has 3 sets of branch leafs instead of the normal 2 .
Good luck and keep us posted